Treating magnesium and alloys comprising the same



Patented Dec. 118, 19

ETE S tartan I PATENT @FIFHCE.

EMIL WOLLNER, OF SCHWANHEIM-ON-THE-MAIN, AND FELK THOMAS, OF FRANK-FORT-ON-THE-MAIN, GERMANY, ASSIGNORS TO THE FIRM: CHEMISCHE FABRIKGBIESHEIM-ELEKTRON, F FRANKFORT-ON-THE-MAIN, GERMANY.

TREATING MAGNESIUM AND. ALLOYS COMPRISING THE SAME.

1T0 Drawing.

To all whom it may concern:

Be it known that we, EMIL VVoLLNnR and FELIX THOMAS, citizens ofGermany, residing at Schwanheim-on-the-Main, Germany,

5 and Frankfort-on-the-Main, Germany, re-

spectively, have invented certain new and useful Improvements inTreating ,Magnesium and\Alloys Comprising Same, of which the followingis a specification.

Our invention refers to the treatment of magnesium and alloys containingit with a view to protecting the metal against atmospheric influences.As is well-known to those skilled in the art, metallic magnesium as wellas most magnesium alloys are subject to oxidation and do not resist theinfluence of the atmosphere. In view of these circumstances an efiectiveprotective coating is of vital importance for their technicalapplicability. Of the metal varnishes commonly used, a very few only canbe employed for magnesium and magnesium alloys inasmuch as the varnishsolvents mostly in use and in many cases even the varnishes them selveswill after a longer or shorter period and in most cases in cooperationwith the moisture of the air react with the metal,

thus causing the varnish coating to get d'ull and ultimately to getdestroyed.

The production of a more or less thick coating of pure magnesiumhydroxide or magnesium oxide as proposed in the German patentspecification No. 347781, does not "offer a suflicient protection, forsuch a 95 coating is not permanently resistive against atmosphericinfluences owing to the hydroxide or the oxide absorbing carbonic acidfrom the air and losing its original resistivity and impermeabilitywhile increasing in volume. Moreover its insulating capacity in the caseof magnesium alloys is inferior to that shown with pure magnesium forthe reason that the foreign metals remain in the oxid coating in afinely subdivided state. Finally in the case of magnesium alloys thecoating appears to be more porous than with pure metallic magnesium.

We have found that a layerof oleate or resinate of magnesium which ispreferably f produced directly upon the metal, for in-' stance by aprotracted treating of the parts to be coated in anoil-water-soap-emulsion or in some other suitable manner, forms aprotective coating of high chemical resis- Application filed May 25,1922. Serial No. 563,718.

tivity and possessing excellent mechanical qualities. Such a coating isunaffected by the air as it will not absorb the carbonic acid containedtherein. On account of its greasy nature which may be due to the factthat small quantities of oil or resin are mechanically retained in thelayer, it does not take on any water, is considerably more elastic thanan ordinary oxid coating, possesses great hardness and resistivityagainst mechanical wear and is capable of being highly polished.

The polishing of the coated parts, whereby a very beautiful,non-metallic lustre is imparted to them, takes place either during theformation of the layer of oleate or resinate by allowing the process totake place in a polishing barrel and if necessary with the addition of asuitable polishing means, or subsequently in a well known manner.

In order to produce coloured coatings, suitable dyes may be added eitherduring the production of the coating, whereby a colouring extendingthroughout the entire coating is obtained, or subsequently by means ofcoloured varnishes.

In order to produce on magnesium or an alloy comprising it a protectivecoating such as above described, we may for instance heat the metal inan emulsionized mixture of about 2 parts by weight of soap, 3 partslinseed oil and 100 parts water. The layer of oleate formed on the metalwill vary in thickness, according to the duration of the treatment, fromabout one hundredth of a millimetre to one millimetre and above that. Itsubstantially consists of magnesium oxide, magnesium oleate and oil inexcess. Coatings of oleate or resinate on magnesium or a magnesium'alloyimpart to the metal the appearance of enamel, horn, or the likeaccording to the colour and polish chosen, and therefore make thesemetals suitable for an extensive application in the manufacture ofartificial horn, buttons and the like. In addition thereto the coatingsrenders these metals adapted for technical purposes also in cases wherethey could not be employed without it, as in consequence of moisture orthe like a too rapid oxidation of the unprotected metal would occur.

We wish it to be understood that we do not desire to be limited to theexact substances and roportions given, for many obvious modi cationswill occur to a person skilled in the art.

We claim:

1. The method of rendering metal containing magnesium resistive againstatmosspheric influences, consisting in forming on the metal a protectivelayer of a magnesium salt of an acid capable of forming a soap.

2. The method of rendering metal containing magnesium resistive againstatmosheric influences, consisting in forming on t e metal a protectivelayer of magnesium 'oleate.

3. The method of rendering metal con- 'taining magnesium resistiveagainst atmospheric influences, consisting in treating the metal with asubstance capable of forming thereon a protective layer of a magnesiumsalt of anacid capable of forming a soap.

4. The method of rendering metal containing magnesium resistive againstatmos-- pheric influences, consisting in treating the metal withasubstance capable .of convertin the skin of said metal into a magnesiumsa t of an acid capable of forming a soap.

5. The method of rendering metal containing magnesium resistive againstatmospheric influences, consisting in treating the metal with asubstance capable of converting the skin of said metal into magnesiumoleate. I

6. The methodof rendering metal con taining magnesium resistive againstatmospheric influences, consisting in treating the metal with anemulsionized mixture of soap, oil'and Water.

7. The method of rendering metal containing magnesium resistive againstatmospheric influences, consisting in treating the metal with anemulsionized mixture of 2 parts soap, 3 parts linseed oil and 100 partswater.

8. The method of rendering metal containing magnesium resistive againstatmospheric influences, consisting in forming on the metal a colouredlayer of a magnesium salt of an acid capable of forming a soap.

9. The method of rendering metal containing magnesium resistive againstatmospheric influences, consisting in forming on the metal a protectivelayer of a magnesium salt of an acid capable of forming a soap andpolishing said layer.

10. As a new article of manufacture, partly worked metal containingmagnesium, said metal 'being provided with a protective layer of amagnesium salt of an acid capable of forming ,a soap.

11. As a new article of manufacture, sheet metal containing magnesium,said sheet metal being provlded with a protective layer of a magnesiumsalt of an acid capable of forming a soap.

12. As a new article of manufacture, sheet magnesium provided with aprotective layer of a magnesium salt of an acid capable of forming asoap.

13. As a new article of manufacture, partly. worked metal Y containingmagnesium, said metal being provided with a protective layer ofmagnesium oleate.

14. As anew article of manufacture, a metallic shape containingmagnesium, said shape being provided with a protective layer of amagnesium salt of an acid capable'of forming a soap. 1

In testimony whereof we atfix our signatures.-

FELIX THOMAS, EMIL WOLLNER.

